Tracker-shifting device for self-playing musical instruments.



L. B. DOMAN. TRACKER SHIFTING DEVICE FOR SELF PLAYING MUSICAL INSTRUMENTS.

APPLIGAITION FILED APR. 19, 1909.

Patented Mar. 16, 1915.

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ZI/Z'Znesses.

UNITED STATES PATENT OFFICE.

LEWIS B. DOMAN, OF ELBRIDGE, NEW YGRK, ASSIGNOR TO AMPI-IION PIANO PLAYER COMPANY, OF ELBRIDGE, NEW YORK, A CORPORATION OF NEW YORK.

TRACKER-SHIFTING DEVICE FOR SELF-PLAYING MUSICAL INSTRUMENTS.

Application filed April 19, 1909.

T all whom it may concern:

Be it known that I, Lnwrs B. DoarAiv, of Elbridge, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Tracker-Shifting Devices for Self-Playing Musical Instruments, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

I This invention relates to certain improvements in tracker shifting devices for self playing musical instruments involving the use of a tracker bar and perforated music sheet, and refers more particularly to manually controlled pneumatic means for shifting one of the parts laterally relatively to the other for restoring normal relation between the music sheet and tracker bar or for transposing the key one or more degrees at any time before or during translation of the musical selection.

I am aware that tracker bars have heretofore been adjusted manually by means of a hand operated screw located in or near the plane of movement of the tracker bar, and, therefore, some distance remote from the system of manuals by which the tempo, expression and like mechanisms are controlled, such system of manuals being usually located in close proximity to the keyboard of the instrument. This screw adjustment is, therefore, not only inconvenient of access, but extremely slow of action and requires close attention to make the desired shift; as, for example, in maintaining proper registration between the music sheet and tracker bar during the playing of a musical selection No. 461,931, filed November 1, 1908.

resulting in Patent No. 939,897, Nov. 9, 19091 In other words, I have sought to effect the operation of the shifting pneumatics by Specification of Letters Patent.

Patented Mar. 16, 1915.

Serial No. 490,786.

varying the air tension therein through the medium of a valve located in such position that it may be operated by the finger or knee of the operator without distracting his attention from the other controlling manuals.

Other objects and uses relating to specific parts of the invention will be brought out in the following description:

In the drawingsFigure 1 is a front elevation of the essential parts of my invention showing separate pneumatics at opposite ends of the tracker bar partly in section. F ig. 2 is an enlarged transverse sectional view through the atmospheric valve chamber taken on line 2-2, Fig. 1, showing the valve and its operating members, and also showing in section portions of the piano case directly in front of the key-board. Fig. 3 is a front elevation partly in section of the mechanism seen in Fig. 2.

The devices shown in the drawings are particularly adapted for what is known as inside players, but the essential elements forming the subject matter of my invention are clearly applicable to outside players, and for the purpose of illustrating its operation I have shown by dotted lines a perforated music sheet 1 as adapted to be moved across the face of a suitable tracker bar 2, said tracker bar being in this instance movable endwise in opposite end supports 3, the latter being mounted upon a supporting shelf 4.

In Fig. 1, I have shown separate shifting pneumatics 5 and -5 mounted in an upright position upon the shelf 1 and provided with very small bleed-holes 6 which are connected by larger conduits 7 to an exhaust conduit 8, the latter being adapted to be connected to any suitable air exhaust device not necessary to herein illustrate or describe. The interiors of these pneumatics are connected by separate conduits 9 and 9 to separate valve chambers 10 and -10' which are adapted to be opened to the atmosphere but are normally closed by valves 11-.

reotly upon a shelf 18 forming a part of the usual piano case and extended under the key-board, as'-1 l.

In Fig. 2 I have shown a portion of a front rail l5- of the piano'case as chambered out at 16 and provided with a swinging section -17- hinged at its lower edge at 18 to form when closed a continuation of the rail -15 for the purpose of concealing the valve and their operating manuals, said swinging section being rocked forwardly and downwardly to the position shown when playing a musical selection to permit access to the valve operating manuals.

In the device shown in Figs. 1, 2 and T have shown each valve l1- as provided with an upwardly projecting finger piece or manual 19 within the chamber 16 and as also provided with a pendant arm or lever 20' projecting some distance below the shelf 13- into the knee space the under side of said shelf where it may be engaged and rocked laterally by the knee of the operator against the action of the spring -12 to open the valve, the finger pieces 19 being engaged and operated by hand for the same purpose when desired. It is evident, however. that the levers -20 may be operated by hand as the operator may elect. These levers and valves, therefore, constitute what I choose to term manually operated means for controlling the action of the shifting pneumatics, the term manual being used in its broadest sense to indicate any device actuated by the operator for opening the pneumatic to the atmosphere. One end of the tracker bar 2- is connected by a link 21 to the movable side of the pneumatic 5, while the opposite end of said tracker bar is connected by a link 21"' to the movable side of the opposite pneumatic 5. The pneumatics -5 and 5 are preferably of the same size or capacity, and when the tracker bar and music sheet are in normal relation, are partially distended to the same degree and retained in such partial distended position by the links -2l and 21. pneumatics are susceptible to movement in either direction from their normal positions,

and, therefore, determine the range of adjustment of the tracker bar, which is only limited by the capacity of the pneumatics. The valve ports, ducts and bleed-holes communicating with the shifting pneumatics are so relatively proportioned to each other and to the capacitv of the pneumatics as to cause a comparatively slow or steady action of said pneumatics and tracker bar connected thereto, so as to enable the operator, through the medium of one or the other of the valves 11, to effect any desired degree of movement-of the pneumatics and tracker bar by mere light pressure of the finger or knee in The shifting opening the necessary valve. The endwise movement of the tracker bar isresisted more or less by its own inertia and friction in its guides, and also by the numerous tubes which are connected to its ducts, and, therefore, it requires some powerconsiderably more than the. mere gravity of the movable sides of the pneumatics to efiect such shifting movement, and it is, therefore, clear that when the pneumatic power is applied to shift the tracker bar by varying the air tension in one or the other of the pneumatics, such tracker bar will remain by its own inertia and friction in its adjusted position, even after the valve 11 is closed, because the air tension in both pneumatics is the same and acts upon the equal areas of the movable sides thereof. The only force operating to return the tracker bar to its normal position is the mere gravity of such movable side, which, however, is disposed in nearly a vertical plane and its gravity is insufficient to counteract the inertia and friction of the tracker bar.

It is now clear that this device as shown in Figs. 1, 2, and 3 is not only positioned for convenience of manipulation without diverting the attention of the operator from the usual system of controlling levers, but

that the pneumatics afford a practical and highly sensitive means of adjustment whereby the tracker bar may be kept in proper registration with the music sheet or may be shifted sufiiciently in either direction to transpose the key one or more degrees above or below normal key. For example, assuming that it is necessary or desirable to shift the tracker bar to the left, either for restoring normal relation between the tracker bar and music sheet or for transposing the key, then all that is necessary to do is to press the finger or knee against one or the other of the operating members for the left hand valve 11 to open the latter, thereby admitting atmospheric air through the" comparatively small duct 9 into the pneumatic 5, and varying or increasing the air pressure in said pneumatic, while that in the opposite pneumatic 5 is below atmospheric pressure, thus causing the movable sides of "both pneumaticsand tracker bar connected thereto to .move in the same direction to the left. The manual or physical pressure upon the valve is then released and the valve allowed to close, thereby preventing further shifting movement of the tracker bar, the pneumatics and tracker bar remaining in this position until one or the other of the valves is again opened. On the other hand if it is desired or necessary to shift the tracker bar to the right, it is simply necessary to open the right hand valve -11 in the same manner as that described for the left hand valve. The ducts and ports connecting the pneumatics to atmosphere are comparatively small. so that the inflation or distention of the pneumatics is comparatively slow but steady which enables the operator to visually follow theimovement of the tracker bar relatively to the music sheet until the proper ports of the tracker bar are registered With the desired rows of perforations in the music sheet, the valve being held open by the operator until the desired shift is effected.

What I claim is- 1. In combination With a longitudinally movable tracker-bar of a self-playing musical instrument, separate pneumatics normally opposing the movement of the trackerbar in either direction, a suction pipe connected to both pneumatics, separate atmosphere ports communicating With said pneumatics, and normally closed valves for said ports adapted to be opened separately by an operator.

2. In combination with a longitudinally movable tracker-bar of a self-playing musical instrument, separate pneumatics normally opposing the movement of the tracker-bar in either direction, a suction pipe connected to both pneumatics, tubes communicating through relatively. small bleed holes With their respective pneumatics and provided with atmosphere ports, and normally closed valves controlling said ports.

In Witness whereof I have hereunto set my hand this 13th day of April 1909.

LEWIS B. DOMAN.

Witnesses:

M. E. ELLIOTT, F. W. DYE.

copies of this patent may be obtained for five cents each, by addressing the Commissioner 0! Patents.

Washington, D. G. 

